I’m a natural-born citizen of the U.S., and an Irish citizen because my grandfather was born in Ireland, and the necessary papers to that effect were obtained.
However,when running for the Presidency I think that any voluntary application you make for citizenship of another country should disqualify you from the office.And if you obtain citizenship of another country through no act of your own...as was true of my Dad and his siblings...I think you must officially and formally renounce that citizenship in order to qualify.